Ratchet mechanism



Dec. l, 1936. RL E, CAMPBELL 2,062,805

RATCHET MECHANISM Filed April 1.5, 1935 Patented Dec. 1, 1936 UNETED ST RATCHET MECHANISM Roy E. Campbell, Claremont, N.

Sullivan Machinery Company,

Massachusetts H., assigner to a corporation of Application April 15, 1935, Serial No. 16,348

23 Claims.

My invention relates to ratchet and pawl mechanisms, and more particularly to ratchet and pawl mechanisms particularly adapted for use in the rotation mechanisms oi rock and other drilling devices.

It is customary to effect the rotation oi the drill steels which are actuated by pneumatic drilling motors, through the employment of ratchet and pawl controlled mechanism which is adapted to effect a partial rotation of a drill steel during one pass of the motor piston, preferably the rearward pass of the latter, and, through the slipping of the pawls over the ratchet, to permit the other, preferably the working, stroke of the piston to be made without rotation of the steel. Such mechanisms commonly involve the provision oi two splined connections between the ratchet and pawl mechanism and the chuck, one of said splined connections being ordinarily helical and the other ordinarily straight. In a generally preferred form of such apparatus, the helical splined connection takes the form oi a rifle nut carried by the motor piston and a rifle bar which at its rear end carries pawls which coact with a stationary ratchet ring. In use, the pawls gradually tend to dull at their corner which engages the teeth of the ratchet ring, and the employment of reversible pawls which may be turned over 'and used with their other edge in engagement with the teeth of the ratchet ring therefore results in a material economy. Such drilling,r motors as have been described are commonly taken apart and cleaned at frequent intervals, and it is beneficial to preclude the slipping of the pawls out of their seats when this is not desired, upon disassembly of the motor.

From one aspect, my invention comprises an improved pawl carrier providing a pawl mounting and carrying a pawl locking device housed entirely within the carrier but accessible through suitable means from the exterior of the pawl carrier to permit movement of the locking device to effect pawl release.

From another aspect, the invention comprises an improved pawl carrier and pawl combination in which a plurality of pawls are supported by the carrier, and alined means, desirably but not necessarily having common yielding positioning means associated therewith, are arranged for resiliently pressing one pawl into operative position and for locking another pawl against accidental removal. This aspect of the invention may obviously be embodied in an internal or in an external type of pawl carrier structure.

From a further aspect, my invention comprises (Cl. 18S-81) the feature of providing a pawl carrier supporting a plurality of pawls and.' having the pawl receiving means therein each provided with a `locking device and having the locking devices for different pawl receiving means differently/arranged, and providing the pawls with a cooperative type of locking device, so positioned thereon that when a pawl is inserted in one position in a pawl receiving means it may be locked by the locking means of the latter, and when positioned in a diiierent pawl receiving means, in reversed position, it may be locked by the locking means of that pawl receiving means.

From still another aspect, the invention comprises the employment of common resilient means for actuating a locking means for one pawl and a pressing device for another pawl. Other aspects of the invention will hereinafter more fully appear.

It is an object of this invention to provide an improved ratchet and pawl mechanism. It is another object of this invention to provide animproved ratchet and pawl mechanism using reversible pawls and having provision whereby the pawls may be locked against accidental displacement irrespective of their mounting in the pawl carrier. It is a further object of the invention to provide an improved resilient pawl pressing means and pawl locking means, the parts of which are interchangeable sothat a locking element maybe used as a pawlplunger and vice versa. It is a still further object of my invention toprovide an improved ratchet and pawl mechanism especially adapted for use in a rock drilling apparatus of the character mentioned above. Itis still another object of my invention to provide an improved ratchet and pawl mechanism in which the pawls are positively locked in position and are not subject to being released by the exertion of a force above a predetermined minimum, but in which, through the use of any suitable thrusting device, even a nail, for example, the pawls may be quickly released when this is desired. Other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawing, in which one embodiment oi the invention is shown for purposes oi' illustration,-

Fig. 1 is a central longitudinal section through a drilling motor in whichv the illustrative form of improved ratchet and pawl mechanism is incorporated.

Fig. 2 is a transverse section on a plane corresponding to the line 2-2 of Fig, 1.

cylinder bore 2 1n which a piston 3` is reciprocable.

section on a plane correline 3-3 of Fig. 1.

View of a pawl detached nected, with a chuck, this structure not being shown, in View of its general familiarity. The piston carries at its rear end a rifle nut 5 with which a rie bar 6 cooperates, and iluid is distributed to the motor through means, not fully illustrated, as it is not necessary to the disclosure of the invenbut including a distributing valve I and a. composite valve chest 8. The rear end of the rie bar 6 is in the form of a pawl carrier I J, which carries two pairs of pawls II, II and iI, II. These pawls, which are made symmetrical in end elevation, cooperate with the teeth I2 of a stationary ratchet ring I3, which is suitably clamped between the valve chest 8 and a rear head I4. The pawls II, II' are suitably pivotally supported in recesses I5, I5 in the pawl carrying portion of the rie bar 6, these recesses being generally cylindrical and opening into spaces I l formed by the cutting away of the periphery of the pawl carrier. Due to the formation of the walls bounding the spaces I'I, the pawls have a limited range of oscillation about their pivotal axes, being free to swing outwardly abundantly far for full engagement with the teeth l2, but restrained from excessive outward movement. To maintain the pawls in yielding engagement with the ratchet teeth I2, pawl plungers I8 are provided, these plungers being disposed in bores I9 extending chordally of the pawl carrier and being pressed yieldingly against the inner sides verse plane of the pawl carrying portion ID; the other two, I Sf, I 9f, forwardly of that plane. Bores ISP, I Bf are parallel to each other, as are bores I 9f, I 9f, and bores I9f, I Sr are perpendicular to a line parallel to bores I9f, I9f.

Each pawl comprises a blade portion 2I and a pivot portion 22, the latter seated in the sockets The bores Il?r and Isf extend nearly completely across the pawl carrying portion I 0; and at their ends in which the plungers I8 do not move, i. e. their inner ends, each intersects the pawl receiving socket of another pawl, each bore herein in- For example, the bores I9f containing the plungers for holding the pawls II in yielding engagement with the ratchet teeth, at their other ends intersect the relatively cylindrical recesses or sockets is oscillatably mounted is intersected by the bore I 9r in which the plunger cooperating with theother pawl II is reciprocable.

Because the offsetting longitudinally from the central transverse plane through the pawl carrier, of the bores I9f and I9f, is equal to the distance by which the notch 23 is oiset from the longitudinal center of each pawl, it will be observed that when a pawl is inserted in one position in a pawl receiving recess, for example, one recess I5, the notch Z3 will come in alinement with a bore I9f, while upon reverse insertion of the pawl in a recess I5', the notch 23 will come into alinement withr a bore I 9F. Accordingly, locking plungers 2lir and 2llf, arranged respectively in the bores I 9r and ISlf, can cooperate with the recesses in the pawls to lock the latter in position. The same springs 20 which are used yieldingly to press the pawls into engagement with the ratchet teeth, also hold the locking plungers in position. The bores I9r and I Bf are, as noted above, not drilled completely through the pawl carrier, and they have shoulders 25 at their ends which open into the pawl receiving recesses, and these shoulders position the locking plungers in the desired manner. Small openings 26 extend from the ends of the bores I Sr and I 9f through the periphery of the pawl carrier, axially of the bores.

The mode of operation of the device will bev what has been said. It. Will be noted that the two pawls I I are yieldinglyA readily understood from pressed into cooperating relation with the ratchet teeth ,by what, for distinction, may be called pressure plungers, I8, while they are locked by alined locking plungers 24f. The pawls I I pressed against the ratchet teeth by other pressure plungers I8, and locked by other locking plungers 2dr. As the parts are assembled, the notches 23 1n the pawls II are in advance of the transverse median plane of the portion Ii) of the rifle bar, and the notches 23 in the pawls Il are to the rear of that same plane. It will be noted that either pawl II might be turned end-for-end and used in the place of a pawl II', and that either pawl II might be turned over and used in the place of either pawl It will be noted, moreover, that any preshaving provision whereby are yieldingly opposite pawls in pairs, as illustrated, is not essential. It will be observed that the structure is simple, requires a minimum number of different parts, is of sturdy construction, and is Very y Well adapted for its intended purpose.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form is shown for purposes of illustration only, and that the invention may be modied and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In combination, a ratchet ring, a pawl carrier arranged within said ratchet ring, diametrically opposite pawls carried by said pawl carrier and engageable with said ratchet ring, and alined relatively movable means respectively for locking one pawl on said pawl carrier and yieldingly pressing another into engagement With the ratchet ring.

2. In combination, a ratchet ring, a pawl carrier arranged Within said ratchet ring, diametrically o-pposite pawls carried by said pawl carrier and engageable With said ratchet ring, and alined relatively movable means yieldingly pressed apart respectively for locking one pawl on said pawl carrier and yieldingly pressing another into engagement With the ratchet ring.

3. In combination, a ratchet ring, a pawl carrier disposed therein, pawls oscillatably carried at dierent positions thereon by said pawl carrier and having locking notches therein, and locking means supported by said pawl carrier and respectively engageable with the notches of said different pawls, said notches and locking means so disposed that reversal of a pawl upon transposition thereof from one position on said pawl carrying means to another will effect cooperative relation between the locking means at said latter position and the notch in said pawl.

4. In an apparatus of the character described, a ratchet ring, a pawl carrier disposed therein and providing a plurality of pawl receiving recesses, pawl locking means including plungers yieldingly maintained in a position in which they project into the bottoms of said recesses, and pawls having pivot portions provided with notches engageable by said locking means.

5. In an apparatus of the character described, a ratchet ring, a pawl carrier disposed therein and providing a plurality of pawl receiving recesses, pawl locking means including plungers yieldingly maintained in a position in which they project into said recesses, and pawls having pivot portions provided with notches engageable by said locking means, the locking means associated with some recesses being differently disposed longitudinally of said recesses than those for other recesses.

6. In an apparatus of the character described, a ratchet ring, a pawl carrier therein supporting at least one pawl, and relatively movable means respectively for pressing said pawl into engagement with said ratchet ring and for locking said paWl against accidental removal from said pawl carrier, including interchangeable relatively movable pressure and locking plungers.

7. In an apparatus of the character described, a ratchet ring, a pawl carrier therein carrying pawls each of which has a blade and a root, and means for pressing said pawls into engagement with said ratchet ring and for locking said pawls against accidental removal, including interchangeable pressure and locking plungers reof said pawls.

8. In an apparatus of the character described, a ratchet ring, a pawl carrier therein carrying pawls each of which has a blade and a root, and means for pressing said pawls into engagement with said ratchet ring and for locking said pawls against accidental removal, including interchangeable pressure and locking plungers respectively cooperating With the blades and roots of said pawls and yieldingly pressed apart.

9. In combination, a pawl carrier having a pawl receiving recess including a bore for receiving a cylindrical portion of a pawl, a locking plunger Wholly housed Within said carrier and moving in a path intersecting said bore, a pawl having a notch to receive said locking plungen.A

and means affording access to said plunger from the exterior of the pawl carrier to enable movement of the latter out of intersecting relation to said recess.

10. In combination, a ratchet ring, a pawl carrier, a reversible pawl associated with said ratchet ring, and means carried by said pawl carrier for locking said reversible pawl against accidental removal from said pawl carrier in reversed positions of said pawl.

11. In combination, a ratchet ring, a pawl carrier, a reversible pawl associated With said ratchet ring, and means for locking said reversible pawl against accidental removal from said pawl carrier in reversed positions of said pawl, said locking means cooperating with said pawl at a point between the ends thereof.

12. In combination, a ratchet ring, a pawl carspectively cooperating with the blades and roots rier, a reversible pawl associated With said ratchet ring, and means for locking saidI reversible pawl against accidental removal from said pawl carrier in reversed positions of said pawl, said locking means cooperating with said pawl at a point between the ends thereof but spaced from the center thereof.

13. In combination, a ratchet ring, a pawl carrier arranged within said ratchet ring, pawls carried by said pawl carrier at different points around the periphery thereof and cooperating with said ratchet ring, and alined relatively movable means respectively for locking one of said pawls on said pawl carrier and for yieldingly pressing another into engagement With the ratchet ring.

14. In combination, a pawl carrier having pawls pivotally mounted thereon in spaced positions, means for locking one of said pawls against removal, and alined means for yieldingly pressing another of said pawls into operative position.

15. In combination, a pawl carrier having pawls pivotally mounted thereon in spaced positions, yieldingly positioned means for locking one of said pawls against removal, and alined means for yieldingly pressing another of said pawls into operative position, said locking and pressing means having a common spring for positioning both of them.

16. In an apparatus of the character described, a pawl carrier supporting a pivotally movable pawl, and means carried by said pawl carrier for pressing said pawl into operative position and for locking said pawl against accidental removal, including interchangeable pressure and locking plungers.

17; In an apparatus of the character described, a pawl carrier supporting a pivotally movable pawl, and means carried by said pawl carrier for pressing said pawl into operative position and for locking said pawl against accidental removal, including interchangeable pressure and llocking devices.

18. In combination, a paWl carrier, a reversible pawl, said carrier having a pair of spaced sockets in which said paWl is interchangeably receivable, and locking means associated with each socket, but in diierent relative positions with respect to the latter, said paWl having cooperating locking means thereon and arranged :blade providing symmetrically disposed opposite edges adapted to cooperate with a ratchet ring, and having a locking portion symmetrical With respect to plane including the axis of the root of the pawl and bisecting the blade thereof.

21. In combination, a ratchet ring, a pawl carrier arranged Within said ratchet ring, paWls carried by said pawl carrier and engageable With said ratchet ring, relatively movable plungers mounted on said pawl carrier and respectively engaging one of said paWls for locking the same on said pawl carrier and engaging another pawl for pressing the latter into engagement with the ratchet ring, and means yieldingly acting on said plungers for pressing the same apart.

22. In combination, a ratchet ring, a paWl carrier arranged Within said ratchet ring, pawls .carried by said pawl carrier and engageable With said ratchet ring, alined relatively movable plungers mounted in said pawl carrier and one engaging one pawl for locking the latter on said pawl carrier and the other engaging another pawl for pressing the latter into engagement with the ratchet ring, and means acting between said plungers for yieldingly pressing the same apart.

23. In an apparatus of the character described, a ratchet ring, a pawl carrier therein supporting at least one pawl, a pair of plungers engaging said pawl, one plunger pressing said pawl into engagement with said ratchet ring and the other plunger locking said pawl against accidental removal from said pawl carrier, and means for yieldingly urging said pressing plunger into engagement with said paWl.

ROY E. CAMPBELL. 

